Red azo dye and process of making same.



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RUDOLF soHULE, or FRANKFORT-ON-THE-MAIN, GERMANY.

RED AZO DYE AND PROCESS OF MAKING SAME.

Specification of Letters Patent.

Patented Dec. 17, 1907..

Application filed October 6. 1906. Serial No. 337,831.

To all whom it may concern:

Be it known that I, RUDoLF SCHI'JLE, doctor of philosophy, 'a citizen of Prussia, and a resident of Frankfort-on-the-Main, in the Province of Hesse-Nassau and Kingdom of Prussia, Germany, have invented certain new and useful Improvements in Red Azo Dye and Processes of Making Same, of which the following is a specification.

They are derivatives of naphthimidazol.

The process is illustrated by the following example: 12.1 kilos m-amidobenzaldehyde are dissolved in water by heating with about a phenyldihydrothe-theoretical quantity of sodium bisulfite,

the solution then being mixed with a solution of 25.4 kilos 1.2-dian1ido5-naphthol-7-sulfonicacid. It is then brought to boiling and kept at boiling temperature for about an hour. The mixture is then acidulated with hydrochloric acid,- and the sparin ly soluble precipitate which has been forme( is filtered off .and washed.- The precipitate is then dissolved by the addition of carbonate of soda, the solution is made alkaline, and cooled;

thereupon the diazo solution of 9.3 kilos anilin, produced in the usual manner, is allowed to run in. The sparingly soluble coloring matter is filtered off, mlxed up with Water and then 50 kilos hydrochloric acid of 21 Be. are added at 0 C. 7.1 kilos nitrite are etc., more bluish shades result.

left standing for some time at 0 C. The diazo compound is then introduced into the cold solution of 25 kilos 2.6-naphtholsulfonicacid, kept alkaline with soda; the dyestuif is formed immediately. The diazo dyestuif thus obtained is rather easily soluble in water and can be completely precipitated from the aqueous solution by common salt. It dyes unmordanted cotton scarlet red shades.

then gradually introduced, and the whole is These dyeings possess a good fastness to washing and li t, and especially a prominent resistance to acids.

Example II. The product obtained by condensing 12.1 kilos m-amido benzaldehyde bisulfite and 25.4 kilos 1.2. diamido-5-oxynaphthalene-7-sulfoacid is dissolved in water by means of 11.5 kilos caustic soda lye (40 B.); 7-1 kilos nitrite of sodium are added, and the solution is allowed to run into 30 kilos hydrochloric acid diluted with water and cooled with ice. The diazo com ound thus obtained is introduced into the al aline solution of 25 kilos 2.6. naphtholsulfoacid. l

dyestuff is completed, a solution of.9.3 kilos diazotized ailililfis added. The diazo dyestufi' thus produced is identical with that described in the first exam le. a

If the anilin is replace by its homologues, halogen derivatives, alkyloxyderivatives, Analogous coloring matters are also obtained if other alpha or betanaphthol-monoor disulfoaoids are substituted for the 2.6-naphtholsulfoacid' Having now particularly described. and,

' As soon as the formation of the monoazo ascertained the nature of my said inventionand in what manner formed, V I declare that what I claim is:

1. The herein described improvement in the manufacture of m. amidobenzaldehyde bi'sulfite and 1.2. dia'mido 5. oxynaphthalene 7. sulfoacid with a diazo compound and a naphthol sulfoacid.

2. The coloring matter obtained by combining a diazo-compound of a primary aromatic amin withthe product of condensation of 1.2. diamido-5-oxynaphthalene-7-sulfonic acid and m. amidobenzaldehyde bisulfite;

further diazotizing the monoazodyes and combiningwith the same is to be per-j dyestuffs which consistsin combining the product of condensation ofp th lsulf oacid;' hi hi i:

2 873393 a di'ystate forms a brown powder, dissolving Prussia, Germany, this 15th day of Septem in concentrated sulfuric acid with a clarev be1',A. D. 1906.

red color and dyeing unmordanted cotton in RUDOLF SOHULE. red shades fast to washing and acids, sub- Witnesses: 5 stantiall as described. JEAN GRUND, Signe' at Frankfort-onthe-Ma.in in the CARL GRUXD.

Province of Hesse Nassau and Kingdom'of 

